The use of structures for absorbing energy in vehicles is known. Bumper systems typically extend widthwise, or transverse, across the front and rear of a vehicle and are mounted to rails that extend in a lengthwise direction. Many bumper assemblies for an automotive vehicle include a bumper beam and an injection molded energy absorber secured to the bumper beam. The bumper system generally further includes an energy absorber along the surface of the bumper and also a fascia for covering the energy absorber.
Beneficial energy absorbing bumper systems achieve high efficiency by building load quickly to just under the load limit of the rails and maintain that load constant until the impact energy has been dissipated. Energy absorbing systems attempt to reduce vehicle damage as a result of a collision by managing impact energy absorption. Bumper system impact requirements are set forth by United States Federal Motor Vehicle Safety Standards (US FMVSS), Canadian Motor Vehicle Safety Standards (CMVSS), European EC E42 consumer legislation, EuroNCAP pedestrian protection requirements, Allianz impact requirements and Asian Pedestrian Protection for lower and upper legs. In addition, the Insurance Institute for Higher Safety (IIHS) has developed different barrier test protocols on both front and rear bumper systems. These requirements must be met for the various design criteria set forth for each of the various automotive platforms and car models.
Past vehicle design trends called for streamlined fascias for a given vehicle platform and designs provided plenty of space between the fascia and the bumper beam for design of effective energy absorbers. However, current trends in bumper system designs allow consumers to have substantially more customized options. That is, for example, different styles of fascias are being designed for many more car models. The design of unique fascias results in relatively low volume manufacturing for each specific car build and tooling costs for injection molding the parts become prohibitive.
Another problem is that current designs have less space, or packaging space, in which energy absorbers can effectively meet the impact and safety requirements. Known energy absorber structures include, for example, foamed plastic materials, plastic ribbed structures, such as polypropylene honeycomb, and deformable hollow bodies. These current structures are expensive and/or do not meet the performance requirements.